Beetles (Order Coleoptera) are the most diverse order of the insects (Phylum Arthropods, Class Insecta). Beetles are, in fact, the most diverse group of animals in the world.

Beetles are easily recognized by their hardened fore-wing covers (elytra), which can be very colourful… or not, and in some cases can be shortened as in rove beetles. They are commonly seen living around us, both indoors and outdoors.

The majority of beetle diversity in the NWT occurs in the boreal forest, but there are many species found north of the treeline. For example, the aquatic predaceous diving beetles (Dytiscidae) are particularly common in tundra ponds and at lake edges.

Beetles are extremely important members of terrestrial and freshwater ecosystems in the North, as they act as predators, detritivores, herbivores, fungivores, scavengers, and prey for other animals.

Studying insects in northern habitats is important for addressing ecological and environmental questions critical in our understanding of northern ecosystems. Our region is experiencing the effects of climate change at a very high rate, so it is crucial to understand how a warming North will affect animal diversity and the general “health” of northern ecosystems.

Studying insects also can help identify effects of human activity on the environment. For example, insects can be bioindicators for pollution. We can also address questions about evolution and how northern biodiversity developed over time, and also in light of past variations in the environment.

The list of beetles included in the NWT General Status Ranks was constructed from both historical records from decades of concerted effort by people interested in understanding biodiversity in the NWT and recent biodiversity monitoring projects.

Early beetle surveys in the North were conducted by highly productive professional entomologists such as Carl Lindroth and George E. Ball in the late 1950s and 1960s. These studies were included in the publication of seminal “The Ground Beetles of Canada and Alaska” in 1969. Since then, research projects have increased our understanding of northern beetle diversity and biology. We are continually updating information.

Citizen scientists (including amateur naturalists to professional entomologists) have a very important place in insect monitoring. Every record of insects in the NWT is informative: species newly described and wider species ranges can results from these efforts.

Collecting insects can be very rewarding. If you do collect beetles, be sure to include information on the collection location, time, date, and habitat where you collected the insect. Specimens can be identified using identification keys – many of these are available online or take your specimens to an elder or an entomologist.

The rove beetles (Family Staphylinidae) are the most diverse family of beetles in the NWT. Rove beetles range in size from about 1 mm to almost 4 cm. They are easily distinguished from other beetles by their short elytra – causing them to initially appear similar to earwigs (minus the cerci, or “pincers” on the abdomen, characteristic of earwigs). The short elytra leave most of the abdomen exposed, but still function as covers for the hind wings, which are tucked up under them.

Many species are Holarctic (occur in the Palearctic (northern Europe and Russia) as well as the Nearctic (northern Canada and Alaska). Although the family is easy to identify on sight due to their elytra, identifying the species often requires the dissection of genitalia – which necessitates a good microscope and a steady hand. Many rove beetles can fly, but there are also species that have lost the ability. Regardless, they are active predators of other insects. They prefer moist habitats, and are commonly found on or in leaf litter, and on many different substrates in most ecosystems. Rove beetles are even found in the far north and above the tree line. Once you can recognize a rove beetle, and know what to look for, you will see them everywhere. Predaceous diving beetles (Family Dytiscidae) are some of the most common beetles in our freshwater habitats. They are typically oval in shape, with a flattened streamlined body, well adapted for swimming. They range in size from 1 mm to over 4 cm.

As with all insects, they are under-studied and the current species diversity is underestimated. Also, there are likely undescribed species and more species are expected with our warming climate. Predaceous diving beetles are fast swimmers and are predatory, sometimes even cannibalistic. Adults are capable flyers, making dispersal to new water bodies easy, and a possible reason for their abundance in the North where there are lots of lakes and tundra ponds to inhabit. Many species can co-exist in a single pond, possibly in part due to their different habitat preferences, for example: shallow versus deeper water, and body sizes (which dictates prey size and type) of the various species. Like the adults, the larvae – known also as “water dragons” – are highly effective predators. The larvae can be found in the shallow waters of many ponds, waiting and watching for movement and possible prey items. They watch but not with real “eyes” but rather with simple photo receptors, or eye spots.

Predaceous diving beetles can be found in almost any freshwater body, providing they can avoid other predators such as fish and dragonfly larvae, and there are food resources available.

Possible threats to the dytiscids of the NWT include climate change and the ecology of the arctic and subarctic is also changing. Permafrost thaw, increasing water temperatures and change in snow cover is affecting their habitat. Naturally rare species, such as the aurora water beetle (Hydroporus aurora) and the pale agabus beetle (Agabus pallens) may be more sensitive to these habitat changes as they only live in northern North America.

Whirligig beetles (Family Gyrinidae) are found on the calm waters of lakes and ponds where they can be seen feverishly swimming in tight circles and other intricate patterns. In fact, their name “gyrinid” refers to these gyrations. Similar to predaceous diving beetles, adult whirligigs are capable of diving, breathing via an air bubble held under their elytra (hardened front wings),

their bodies are smooth, oval, generally black, or dark coloured, and streamlined. If you are able to collect a whirligig beetle and you can take a close look, you will notice that in addition to legs well adapted for swimming, their eyes are divided into an above water, and a below water “eye”. What is amazing about these physical adaptations is that they appear on ancient whirligig beetle fossils dated to the mid-Jurassic (~175-163 million years ago)! Both whirligig swimming behaviour, and visual adaptations, make them excellent predators of other aquatic invertebrates. Like predaceous diving beetles, whirligig beetles rely on ponds and lakes (or slow moving waters), and a loss of tundra pond and lake habitats could greatly affect the abundance of these fascinating beetles.

Blister beetles (Family Meloidae) are also called oil beetles, because they will extrude oil from their joints when threatened. This oil contains the poison cantharidin, which can burn and cause blisters on contact. Members of the genus Meloe are eye-catching and unmistakable. They are characterized by a very large abdomen relative to their head and thorax. Their forewings (elytra) sit at the top of the abdomen so that the shape is reminiscent of an 18th century ladies dress with a bustle. The species found in the NWT are black in colour. All species of blister beetles have “hypermetamorphic” larvae, meaning that the immature beetles go through several stages before pupating and reaching maturity. Meloid larvae are mobile: they attach themselves to pollinating bees to get carried back to the bee’s nest where they feed on bee larvae, or the resources available in the nest. These beetles are dependent on healthy pollinating bee populations.

Hide beetles (Family Trogidae) are scavengers and tend to be one of the last types of scavenging insect to visit carrion – where they feed on the dried remains of skin, feathers, or fur – giving their name “hide” as in animal hide – beetles. Both adults and larvae feed on keratin, making them the only members of the super-family Scarabaeoidea to have this capability, and certainly making them integral for recycling nutrients into the soil. Hide beetles are small, and lumpy in appearance. They tend to cover themselves in soil and sit very still when disturbed – making them very difficult to detect.

There are 1,140 species of beetles confirmed present in the NWT, and of these, 26 species are alien to the NWT. An additional 12 species are expected to be present.